This invention generally relates to apparatus and methods for testing and indicating the strengths of muscles; and, more specifically, to apparatus and methods especially well-suited to test and indicate the strengths of individual muscles and the comparative strengths of corresponding muscles.
Recently, equipment has been developed to objectively and quantitatively measure the strength of individual muscles. As a therapeutic tool, such devices are very helpful in that they help a therapist identify specific muscles that need to be strengthened and to design a program that will help those particular muscles. Moreover, a quantitative measurement will tell not only which muscles are weak, but also how weak those muscles are. Further, as a person is undergoing treatment, an objective measure of the progress he or she is making, first, helps the therapist modify the treatment program, if necessary, and second, allows the patient to witness personally the fact that his or her muscles are getting stronger with therapy, which often encourages the patient to continue the treatment. In addition, often a patient may believe he or she is fully recovered and will discontinue treatment. An accurate, quantitative and objective measure of the strength of each muscle may show otherwise, however, and convince the patient to continue treatment.
As an exercise training tool, an objective and quantitative measurement of the strength of individual muscles will help a person or a trainer develop a highly personalized exercise program that concentrates on the muscles that need the most work. Occasional retesting will enable an individual to observe personally the progress he or she is making, and will help show how effective a particular exercise program is and, if it becomes advisable to do so, how a program should be modified. An individual may test and record the strengths of his or her muscles while healthy to provide a personal standard; and if that person is later injured, he or she, while recovering, can compare his or her muscle strengths against that recorded standard to determine whether the muscles have adequately recovered before resuming a particular activity, thus lessening the risk of a re-injury or of a new injury.
One prior art device for testing and indicating the strengths of individual muscles and muscle groups is disclosed in copending U.S. application Ser. No. 869,135, filed May 30, 1986. The apparatus disclosed in this copending application may be effectively employed to provide an objective and quantitative indication of the force developed by muscle over a period of time; nevertheless, it is believed that this prior art device may be improved upon in several respects. In particular, this prior art apparatus includes a pressure pad mounted on a horizontal support arm, that, in turn, is connected to a vertical guide post. The pressure pad is filled with a gas such as air and is connected to a transducer that generates an electric current in response to the pressure in the pressure pad. In use, a subject applies a force to the pressure pad, and the transducer then generates a current responsive to that force.
The pressure pad, though, is not movable along the length of the horizontal support arm, and the lateral position of the guide post is not readily adjustable, and the utility of the prior art device could be improved by increasing the maneuverability of the pressure pad and the guide post. Also, the current generated by the transducer is not linearly related to the force applied to the pressure pad, and this limits the usefulness of that current. In addition, the prior art apparatus is not specifically designed to automatically produce a permanent copy of the indication of the force developed by the muscle, or to automatically provide a display comparing one test result with another.